Functionalized polyorganosiloxanes or silanes for the treatment of lignocellulosic materials

ABSTRACT

The present invention relates to functionalized polyorganosiloxanes or silanes for the treatment of lignocellulosic materials.

The present invention relates to functionalized polyorganosiloxanes orsilanes for the treatment of lignocellulosic materials that are suitableto preserve wood and other materials based on cellulose and/or lignin,and particularly to protect them against weather conditions,microorganisms, insects and fungi. Furthermore, the water absorption oflignocellulosic materials, particularly wood, is increased, theshrinkage behavior of lignocellulosic materials, particularly wood, isimproved, by the use of the polyorganosiloxanes or silanes according tothe present invention. Furthermore, by using the polyorganosiloxanes orsilanes of the present invention an insecticidal equipment can beachieved, which makes the use of conventional insecticides unnecessary.

BACKGROUND

It is known to increase the resistance of wood against weatherconditions by a coating of lacquer and color paints. Dimensional changesof the wood, for example caused by swelling and shrinkage due to waterabsorption or release, caused by external humidity changes, neverthelesslead to peeling of such paints.

It is further known, to protect the optical appearance and theresistance of wood against harmful microorganisms, for example blueingfungi or white rot, brown rot and soft rot, by an impregnation with amixture of arsenic, ionic copper and chromium VI.

Such wood preservatives are disadvantageous for the reason that at leastchromium and arsenic are harmful and toxic for the environment. Evencopper complexes and boron compounds are now seen as critical under thesame aspects.

Furthermore, water-soluble wood preservatives are known which comprise aquaternary ammonium compound such as for example benzalkonium chloride.Such wood preservatives are disadvantageous as they are deposited onlyin the upper layers of the wood due to their immediate bonding to wood.

Further biocidal actives are 3-iodo-2-propynyl butyl carbamate (IPBC) ortriazoles (propiconazole, tebuconazole).

The known organic wood preservatives are used in the applicationcategories 1, 2 and 3 according to DIN EN 351 and do not lead tohydrophobing the wood so that the tendency of the wood to absorb waterand therewith the dimensional stability remain unchanged.

To reduce the water absorption of wood, essentially compounds based onoils, fats and waxes (paraffins and silicones) were used.

Known wood preservatives, which are used for hydrophobing and which havea content of silicon compounds, are known too. Thus, JP 2002-348567 Adescribes wood preservatives, which consist of a mixture of differentalkoxysilanes, including amino group containing alkoxysilanes and boricacid.

U.S. Pat. No. 6,294,608 discloses aqueous emulsions for treating mineralconstruction materials and wood with a mixture of silanes which havealkyl and alkoxy groups or aminoalkyl groups. Polysiloxane compounds arenot disclosed.

EP 0716127 discloses polyorganosiloxanes as well as aqueous mixturesthereof, which are particularly used for hydrophobing surfaces, e.g. inthe impregnation of leather and textiles made from natural and/orartificial materials and in the field of organic and mineralconstruction materials as well as building protection.

EP 0716128 discloses aminoalkyl alkoxysilanes which can be used amongothers for hydrophobing cellulose products or as additives for paintsand lacquers. Polyorganosiloxanes are not disclosed therein.

US 2002/0026881 describes a composition for hydrophobing surfaces whichcontains silicone among others.

U.S. Pat. No. 4,757,106 discloses the combination ofaminoorganosiloxanes with basic nitrogen contents of >0.5% withsiloxanes with a molecular weight of >620 g/mol in substantiallysolvent-free formulations as equipment for mineral substrates.

DE 3447636 discloses the combination of aminoorganosiloxanes with basicnitrogen contents of >0.5% with a second amino siloxane with basicnitrogen content of 0 to 0.5% and optionally a siloxane with molarmasses <600 g/mol in the presence of solvents.

EP 0621115 and DE 4241727 disclose the combination ofaminoorganosiloxanes with basic nitrogen contents of >0.5% withwater-repellent agents, e.g. siloxanes, optionally in the presence of asecond compound with basic nitrogen in contents of 0 to 0.5% for thetreatment of wood. DE 10 2004 036918 proposes the use ofaminoorganosiloxanes in wood preservatives. The siloxanes shall have amolecular weight of 500 to 500,000 g/mol and the degree of substitutionof the siloxane units with amino groups shall be up to 50%.

DE 4202320 describes the impregnation of wood with a non-functionalizedpolydimethylsiloxane by using supercritical carbon dioxide as a carriermedium. The disadvantage of this proposal is that the non-functionalizedpolydimethylsiloxane can be leached from the wood.

EP 680810 describes the modification of wood by acetylation with aceticanhydride at elevated temperatures. The disadvantage of this procedureis an insufficient reduction of the water uptake of the modified wood.

BRIEF SUMMARY OF THE INVENTION

The disadvantage of all of the above suggestions is that a long-lastingprotection of wood in practice can only be achieved with a two-stagetreatment of the wood so far. In the so-called Royal process the wood isfirst impregnated in a first step with an organic copper salt (Cu-HDO)or an organic copper salt, and subsequently in a second step animpregnation with oil is carried out to prevent the leaching of thebiocidal copper.

Siloxanes having hydrolysable groups tend to condensation after contactwith water and acids or bases, which reduces solubility, emulsifyingcapacity and penetration capacity of the wood. Impregnation withsiloxanes as disclosed in DE 10 2004 036918 is not long-lasting, asthese siloxanes can be released again after prolonged exposure to water.

It is therefore an object of the present invention to impregnate woodlong-lasting in a practicable one-step method, and thereby furtherreduce the tendency of wood to absorb water, to improve the dimensionalstability in changing humidity conditions of the environment and toreduce the degradation of the wood by fungi, bacteria and insects, suchas wood destroying insects, for example termites, house longhorn beetle,common furniture beetle, powder post beetle, effectively. At the sametime yellowing and graying of the woods due to light and weather impactshall be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 graphically depicts the mixing ratio of acetoxyfunctionalsiloxane to acetic anhydride in an embodiment of the invention.

FIG. 2 graphically depicts first and second water absorptions after 24hours in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to polyorganosiloxanes and silanes for thetreatment of lignocellulosic materials, in particular wood and otherlignocellulosic materials, to increase their resistance, for exampleagainst microbial degradation or degradation caused by fungi and/orweather conditions such as sunlight (UV rays), rain and otherdimensional variations of humidity. The Polyorganosiloxanes or silanesused in the present invention serve for use as a protective agent forlignocellulosic materials against weather impact, fungi, microbes andinsects. Furthermore, the use of the polyorganosiloxanes or silanes inaccordance with the present invention leads to an improvement of theproperties such as shrinkage and swelling of wood or lignocellulosicmaterials by treating the lignocellulosic materials therewith. In afurther aspect, the present invention relates to lignocellulosicmaterials, in particular wood, which has been treated with thepolyorganosiloxanes and/or silanes used according to the presentinvention.

The polyorganosiloxanes and/or silanes used in the present invention mayin particular be used for the treatment of lignocellulosic materialssuch as wood and wood products, particleboards, medium densityfiberboards, oriented beach boards (OSB), paper, cardboards, insulationboards based on lignocellulose, plywood, veneers and packaging materialwith a content of biodegradable compounds (hereinafter collectivelyreferred to as “lignocellulosic materials”). The polyorganosiloxanesand/or silanes used in the present invention further have a highresistance to leaching after impregnation.

As a further advantage the polyorganosiloxanes and/or silanes used inaccordance with the present invention permit application, such as e.g.by impregnation, in a single process step. Surprisingly, the desiredimprovement is possible with certain organo-functional radicals inshort-chain polyorganosiloxanes or silanes. Amino-functionalizedsilicones are primarily not required.

The present invention thus relates to polyorganosiloxanes or silanes forthe treatment of lignocellulosic materials, characterized in that thepolyorganosiloxanes are straight-chained, branched or cyclicpolyorganosiloxanes, formed from a number average of 2 to 30 siloxyunits, which are selected from the group consisting of:

wherein the radicals R¹ represent organic radicals, which may be thesame or different, with the proviso that at least one of the radicals R¹is a radical R^(F) containing a functional group F, which is selectedfrom the group of functional groups consisting of:

-   -   phosphonium group,    -   epoxy group    -   carbonate group,    -   urethane group,    -   isocyanate group including blocked isocyanate group,    -   urea group,    -   amido group,    -   aldehyde group,    -   hemiacetal and acetal group,    -   an enamine group, or    -   imine group,    -   a zwitterionic group,    -   carboxylic acid/carboxylate group,    -   sulfonic acid/sulfonate group,    -   sulfuric acid half-ester/sulphate group,    -   phosphoric ester/phosphate group    -   phosphonic esters/phosphonate group,    -   phosphorous ester/phosphite group,    -   xanthate/xanthogenate ester group,    -   organo amino group Si-bonded via N,    -   hydroxy group,    -   acyloxy group Si-bonded via O,    -   alkoxy group Si-bonded via O, and    -   thiosulfato group        and characterized in that the silanes are represented by the        formula (I)        Si—(R¹)₄  (I)        wherein the radicals R¹ are as defined above, with the proviso        that at least one of the radicals R¹ is a radical R^(F)        containing a functional group F, which is as defined above, and        at least one of the radicals R¹ is bonded to the silicon atom        via a hetero atom and at least one of the radicals R¹ is bonded        to the silicon atom via a carbon atom,        or by the formula (II)        (R¹)₃—Si—R³—Si—(R¹)₃  (II)        wherein R¹ is the same or different and has the meaning as        defined for formula (I), and R³ is a divalent, straight-chained,        branched, cyclic, aliphatic, unsaturated, or aromatic        hydrocarbon radical having up to 30 carbon atoms, which may        contain one or more groups selected from —O—, —NH—, —C(O)— and        —C(S)—, and which may optionally be substituted by hydroxy and        is bonded to the silicon atom via carbon, and salts thereof.

Preferably, the group of functional groups consists of:

-   -   phosphonium group,    -   phosphine group,    -   epoxy group    -   carbonate group,    -   urethane group,    -   isocyanate group including blocked isocyanate group,    -   urea group,    -   amido group,    -   aldehyde group,    -   an enamine group,    -   a zwitterionic group,    -   carboxylic acid/carboxylate group,    -   sulfonic acid/sulfonate group,    -   sulfuric acid half-ester/sulphate group,    -   phosphoric ester/phosphate group    -   phosphonic acid esters/phosphonate group,    -   phosphorous ester/phosphite group,    -   xanthate/xanthogenat ester group,    -   organo amino group Si-bonded via N,    -   acyloxy group Si-bonded via O,    -   alkoxy group Si-bonded via O, and    -   thiosulfato group.

The polyorganosiloxanes and silanes of the present invention are inparticular characterized in that the radicals R¹ are selected from thegroup consisting of R^(F) and R^(N), wherein the radicals R^(F) are suchradicals R¹ which have the mentioned functional groups F and wherein theradicals R^(N) are such radicals R¹ which do not have the abovefunctional groups F.

In a preferred embodiment of the invention, the polyorganosiloxanes usedin the present invention have a molar content of the radicals R^(F),which comprise at least one functional group F, from 3.33 to 100 mol-%,based on the number of siloxy units. More preferably this content isfrom 5 to 100%, even more preferred 5 to 50%, even more preferred 10 to50% and most preferred 10 to 30 mol-%.

The polyorganosiloxanes used in the present invention suitably have amolar content of branched radicals T and Q of 0 to 50%, preferably 0 to20%, more preferably 0 to 10%, especially 0 to 5%, very especially 0%,based on the total number of siloxy units.

The polyorganosiloxanes used in the present invention suitably have anaverage number of siloxy units (number of silicon atoms) of 2 to 30. Theaverage number of siloxy units in the polyorganosiloxanes used in thepresent invention is for example determined by gel permeationchromatography (GPC) after appropriate calibration, particularly withpolystyrene as standard. Preferably, the average number of siloxy unitsis 2 to 20, more preferably 2 to 15, even more preferred 2 to 12, evenmore preferred 2 to 7.

It is within the scope of the present invention to use mixtures of thepolyorganosiloxanes used in the present invention with one another, aswell as mixtures of polyorganosiloxanes used in the present inventionwith silanes. When using mixtures of polyorganosiloxanes bi-, tri- andhigher modal distributions are formed. In this case, binary mixtureswith a bimodal distribution are preferred. A preferred embodiment isthen the use of mixtures of short chain polyorganosiloxanes having anaverage of 2 to 15 siloxy units and long-chain polyorganosiloxaneshaving 16 to 30 siloxy units. The use of such mixtures is advantageousin that in the lignocellulosic materials different sites of action areoperated. Thus, the long-chain polyorganosiloxanes are preferablylocated in the intercellular spaces (lumens) while the short-chainpolyorganosiloxanes are more accumulated in the cells or cell walls.Overall this leads to a higher active penetration and concentration, andthus an improved effect is achieved.

The functional groups F of the polyorganosiloxanes or silanes used inthe present invention serve both to improve the solubility of thepolyorganosiloxane or silanes in the preferably aqueous formulation, onthe other hand to the anchoring of the polyorganosiloxanes or silanes inthe lignocellulose materials, in particular in the cells and cell wallsof the mentioned materials, particularly for increasing the dimensionalstability of the materials or of the shrinkage behavior in the presenceof swelling solvents, in particular humidity. From these points, thefollowing functional groups F are particularly suitable:

-   -   epoxy group,    -   carbonate group,    -   isocyanate group including blocked isocyanate group,    -   xanthate/Xanthogenat ester group,    -   organo amino group Si-bonded via N,    -   acyloxy group Si-bonded via O,    -   alkoxy group Si-bonded via O, and    -   thiosulfato group.

The organic substituents R¹ of the polyorganosiloxanes or silanes usedin the present invention are suitably selected from the group consistingof:

straight-chain, cyclic or branched, saturated, unsaturated or aromatichydrocarbon radicals having up to 100 carbon atoms, which may optionallycontain one or more groups selected from

—O—,

—S—,

—NR²—, wherein R² represents hydrogen, a monovalent straight-chained,cyclic or branched, saturated, unsaturated or aromatic hydrocarbonradical having up to 60 carbon atoms, which may contain one or moregroups selected from —O—, —S—, —NH—, —C(O)— and —C(S)—, and which mayoptionally be substituted by one or more substituents selected from thegroup consisting of a hydroxyl group, an optionally substitutedheterocyclic group, preferably containing one or more nitrogen atoms,amino, alkylamino, dialkylamino, ammonium, polyether radicals andpolyether ester radicals, wherein in case that multiple groups —N R² arepresent, these may be the same or different, may comprise

wherein R² is as defined above,—P(R²)₂, wherein R² is as defined above,—C(O)— and—C(S)—,and may be substituted by one or more radicals selected from the groupconsisting of:

-   -   hydroxyl,    -   mercapto (—SH or —S⁻),    -   isocyanato,    -   halogen (such as chlorine, fluorine),    -   a polyether radical having up to 60 carbon atoms, which may        optionally contain one or more amino, mono- or dialkylamino, or        arylamino groups,    -   a saccharide-containing organic radical,        or two substituents R¹ from different siloxy units together form        a straight-chained, branched or cyclic alkandiyl radical having        2 to 20 carbon atoms between two silicon atoms, which is        optionally interrupted by —O—, —S—, —C(O)—, —NH— and is        optionally substituted by OH,        wherein the bonding to silicon may be via a carbon atom and/or a        heteroatom.

As mentioned above, these radicals R¹ are selected from the groupconsisting of the radicals R^(F) and R^(N), wherein the radicals R^(F)are radicals R¹ having the mentioned functional groups F and theradicals R^(N) are radicals R¹ not having the mentioned functionalgroups F.

Preferably, the radicals R¹, R² and R³ in the polyorganosiloxanes orsilanes used in the present invention, including R^(F) and R^(N), haveno amino groups. Except for such amino group-containing radicals havinga zwitterionic group such as a betaine or a sulfobetaine group, or suchradicals wherein the amino group is bonded to the silicon atom via thenitrogen atom.

Preferably, R² is hydrogen, a saturated hydrocarbon radical having up to24 carbon atoms, which may contain one or two groups selected from —O—,—S—, —NH—, —C(O)— and —C(S)—, and which may optionally be substituted byone or two hydroxyl groups.

Preferably, R³ is a divalent saturated aliphatic hydrocarbon radicalhaving up to 20 carbon atoms, which may contain one or two —O— groups,and which may optionally be substituted by hydroxy, and which is bondedto the silicon atom via carbon.

The radicals R^(N) preferably include: n-, iso-, or tert.-C₁-C₂₂-alkyl,C₂-C₂₂-alkoxyalkyl, C₅-C₃₀-cycloalkyl, C₆-C₃₀-aryl,C₆-C₃₀-aryl(C₁-C₆)alkyl, C₆-C₃₀-alkylaryl, C₂-C₂₂-alkenyl,C₂-C₂₂-alkenyloxyalkyl, which may all be substituted by one or more(such as one to five) substituents, such as hydroxyl, halogen(particularly fluorine), and which may have one or more ether groups,such as H₃C—, CH₃CH₂—, CH₃CH₂CH₂—, (CH₃)₂CH—, C₈H₁₇— and C₁₀H₂₁—,H₂C═CH—O—(CH₂)₁₋₆, cycloaliphatic radicals such as cyclohexylethyl,limonyl, norbonenyl, phenyl, tolyl, xylyl, benzyl and 2-phenylethyl,halogen(C₁-C₁₀)alkyl, such as C_(f)F_(fn+1)CH₂CH₂— wherein f=1 to 8,such as CF₃CH₂CH₂—, C₄F₉CH₂CH₂—, C₆F₁₃CH₂CH₂—,C₂F₅—O(CF₂—CF₂—O)₁₋₁₀CF₂—, F[CF(CF₃)—CF₂—O]₁₋₅—(CF₂)₀₋₂—, C₃F₇—OCF(CF₃)—and C₃F₇—OCF(CF₃)—CF₂—OCF(CF₃)—.

Particularly preferred are methyl, vinyl, phenyl, 3,3,3-trifluoropropyl,and most preferred is R^(N)=Methyl.

In the polyorganosiioxanes or silanes used in the present invention theradicals R^(F) are preferably selected from the group consisting of:

-   -   quaternary phosphonium groups containing radicals of the        formula:        —R³—P⁺(R²)₃        wherein R³ is as defined above and is bonded to the silicon atom        via carbon, the radicals R² may be the same or different and are        as defined above, and preferably at least one of R² is not        hydrogen,        —R³—P(R²)₂        wherein R³ is as defined above and is bonded to the silicon atom        via carbon, the radicals R² may be the same or different and the        radicals R² are as defined above,    -   epoxy groups containing radicals selected from:

-   -   carbonate groups containing radicals selected from:

-   -   urethane groups containing radicals selected from:        —R³—OC(O)NH—R²    -   wherein R² and R³ are as described above,    -   isocyanate groups containing radicals selected from:        —R³—NCO    -   wherein R³ is as described above,    -   urea groups containing radicals selected from:        —R³—NHC(O)NHR²,    -   wherein R² and R³ are as defined above,    -   amid or amido groups containing radicals selected from:        —R³—NHC(O)—R² or —R³—C(O)NH—R²,    -   wherein R² and R³ are as defined above,    -   enamine groups containing radicals selected from:

(imine form) which may be present as a tautomer when one of the radicalsR² is a hydrogen atom in β-position to the nitrogen atom:

wherein the radical R²* from the radical R² formally results fromshifting of a hydrogen atom, and wherein R² are the same or differentand R² and R³ are each as defined above,which are particularly obtainable by reaction of amino-functionalpolyorganosiloxanes with ketones, such as aliphatic or aromatic ketoneshaving up 20 to 14 carbon atoms, such as C3-C14 aliphatic ketones,aromatic C8 to C12 ketones, further enamines of the formula

-   -   wherein R² and R³ are as defined above,        which are particularly obtainable by reaction of        amino-functional polyorganosiloxanes with monoaldehydes, such as        aliphatic or aromatic aldehydes having up to 14 carbon atoms,        for example, formaldehyde, butyraldehyde, furfural, acrolein,        crotanaldehyde, glycolaldehyde, acetaldol, aromatic C7 to C11        aldehydes, for example benzaldehyde, anisaldehyde, vanillin,        salizylaldehyde,    -   aldehyde groups containing radicals, such as selected from:

-   -   wherein R³ are the same or different and R² and R³ are as        defined above, which are particularly obtainable by reaction of        aminofunctional polyorganosiloxanes with dialdehydes, such as        glyoxal, malonaldehyde, succinaldehyde, phthalaldehyde,        isophthalaldehyde, terephthalaldehyde,    -   hemiacetal and acetal group containing radicals such as those        resulting from the reaction of aldehyde groups containing        polysiloxanes or silanes with monovalent or polyvalent alcohols,        such as methanol, ethanol, glycol    -   zwitterionic group containing radicals such as carbobetaine        groups containing radicals selected from:

or its neutral form:

-   -   and salts thereof,    -   wherein R² and R³ are the same or different and are as defined        above,    -   sulfobetaine groups containing radicals selected from:

or its neutral form:

-   -   and salts thereof,    -   wherein R² and R³ are the same or different and are as defined        above,    -   carboxylic acid/carboxylate groups containing radicals selected        from:        —R³—COOR²,—R³—COO⁻        wherein R² and R³ each are as defined above,    -   sulfonic acid/sulfonate groups containing radicals selected        from:        —R³—SO₃R²,—R³—SO₃ ⁻    -   wherein R² and R³ each are as defined above,    -   sulfuric acid halfesters/sulfate groups containing radicals        selected from:        —OSO₃R²,—OSO₃ ⁻    -   wherein R² is as defined above,    -   phosphoric ester/phosphate groups containing radicals selected        from:

-   -   wherein R² and R³ are as defined above, and    -   fluorophosphoric ester selected from:

-   -   wherein R² and R³ are as defined above,    -   phosphonic esters/phosphonate groups containing radicals        selected from:

-   -   or the protonated forms thereof, wherein R² and R³ are as        defined above, (wherein R³ is bonded to the phosphorus atom via        a carbon atom), and    -   wherein R³ is as defined above,    -   phosphorous ester/phosphite groups containing radicals,

-   -   wherein R² and R³ are as defined above (and are bonded to the        oxygen atom of the phosphorous ester/phosphite groups via        carbon),    -   xanthate/xanthogenate ester groups containing radicals

-   -   wherein R² and R³ each are as defined above,    -   amino groups Si-bonded via N, selected from:    -   —N(R²)₂, wherein R² is as defined above, with the proviso that        at least one radical R² is not hydrogen,    -   hydroxy group,    -   acyloxy groups Si-bonded via O, selected from:

wherein R² is as defined above,

-   -   alkoxy groups Si-bonded via O, selected from:    -   —OR², wherein R² is as defined above,        and the cations, which neutralize the anionic functional groups,        are selected from the group consisting of:        ammonium groups (N⁺(R²)₄, wherein R² is as defined above),        phosphonium groups (P⁺(R²)₄, wherein R² is as defined above) and        mono- to trivalent metal cations,        and the anions, which neutralize the cationic functional groups,        are selected from the group consisting of:        halide,        hydroxide,        borate,        sulphate,        phosphate,        nitrate and        carboxylate.

Particularly preferred groups R^(F) include:

-   -   quaternary phosphonium groups containing radicals of the        formula:        —R³—P⁺(R²)₃    -   wherein R³ is as defined above, bonded to the silicon atom via        carbon, the radicals R² may be the same or different and the        radicals R² are as defined above, and preferably at least one of        the radicals R² is not hydrogen,    -   phosphine groups containing radicals of the formula:        —R³—P(R²)₂    -   wherein R³ is as defined above, bonded to the silicon atom via        carbon, the radicals R² may be the same or different and the        radicals R² are as defined above,    -   isocyanate groups containing radicals, selected from: —R³—NCO    -   Wherein R³ is as described above, and blocked derivatives        thereof, such as lactams, oximes, pyrazoles, sterically hindered        amines or malonic acid ester (C. Gürtler, M. Homann, M.        Mager, M. Schelhaas, T. Stingl, Farbe & Lack, 110. Volume,        December 2004, 34-37),    -   epoxy groups containing radicals, selected from:

-   -   carbonate groups containing radicals selected from:

-   -   carbobetain groups containing radicals selected from:

or its neutral form:

-   -   wherein R² and R³ are the same or different and are as defined        above,    -   sulfobetain groups containing radicals selected from:

or its neutral form

-   -   wherein R² and R³ are the same or different and are as defined        above,    -   carboxylic acid/carboxylate groups containing radicals selected        from:        —R³—COOR²,—R³—COO⁻    -   wherein R² and R³ each are as defined above,    -   sulfonic acid/sulfonate groups containing radicals selected        from:        —R³—SO₃R²,—R³—SO₃    -   wherein R² and R³ each are as defined above,    -   phosphonic acid esters/phosphonate groups containing radicals        selected from:

-   -   wherein R³ are as defined above,    -   phosphorous ester/phosphite groups containing radicals

-   -   wherein R³ is as defined above,    -   xanthate/xanthogenate ester groups containing radicals

-   -   wherein R² and R³ each are as defined above,    -   amino groups Si-bonded via N, selected from:    -   —N(R²)₂, wherein R² is as defined above, with the proviso that        at least one radical R² is not hydrogen    -   acyloxy groups Si-bonded via O, selected from:

wherein R² is as defined above,

-   -   alkoxy groups Si-bonded via O, selected from:    -   —OR², wherein R² is as defined above, except hydrogen.

Preferred cations which neutralize the anionic functional groups areselected from the group consisting of:

Ammonium groups (N⁺(R²)₄, wherein R² is as defined above),

phosphonium groups (P⁺(R²)₄, wherein R² is as defined above), and mono-to trivalent metal cations, such as for example Na⁺, K⁺, Fe²⁺, Fe³⁺,Al³⁺, Cu²⁺, Zn²⁺ und Cr³⁺.

Preferred anions which neutralize the cationic functional groups areselected from the group consisting of:

halide,

hydroxide,

borate,

sulfate,

phosphate,

nitrate and

carboxylate.

Polyorganosiloxanes according to the present invention preferablycontain at least one radical of the formula M^(F):

wherein R¹ is as defined above, preferably R^(N) as defined above, andR^(F) as defined above.

In a further preferred embodiment polyorganosiloxanes are used havingthe formula:

wherein n1+n2=1 to 28, preferably 1 to 20, more preferably 1 to 15, morepreferably 5 to 15, and n2≥0, preferably 1 to 28, more preferably 1 to10, more preferably 1 to 5, and R¹ and R^(F) are as defined above.

Particularly preferred are polyorganosiloxanes according to the presentinvention having the formula

Wherein n is in number average 0 to 28, preferably 0 to 20, morepreferably 0 to 15, more preferably 5 to 15, and R¹ is as defined above,preferably R^(N) as defined above, and R^(F) is as defined above.

In a further preferred embodiment polyorganosiloxanes are used havingthe formula:

wherein n1+n2=1 to 28, and n2≥1, preferably 1 to 28, more preferably 1to 10, more preferably 1 to 5 and R¹ and R^(F) are as defined above.

In a further preferred embodiment cyclic polyorganosiloxanes are usedhaving the formula:

wherein n1+n2=3 to 7 and n2≥1, preferably 1 to 7, more preferably 1 to5, particularly preferably 1 to 3 and R¹ and R^(F) are as defined above.

It is further possible that the radical R^(F) is located on a siliconatom, which forms a T-unit.

In a further preferred embodiment of the invention, several types of theinventive compounds are used simultaneously.

The polyorganosiloxanes or silanes of the present invention may be usedin combination with other polyorganosiloxanes or silanes different fromthose of the present invention. Such polyorganosiloxanes or silanes,which are different from the polyorganosiloxanes or silanes according tothe present invention, may for example also comprise functional groupswhich are different from R^(F), and which for example comprise aminogroups (NH₂, NHR¹, NR¹ ₂, wherein R¹ represents an organic radical) orammonium groups (NH₄ ⁺, NR¹H₃ ⁺, NR¹ ₂H₂ ⁺, NR¹ ₃H⁺ and NR¹ ₄ ⁺, whereinR¹ represents an organic radical).

Therein, a combination of polyorganosiloxanes or silanes with basicfunctional groups and polyorganosiloxanes or silanes with acidicfunctional groups are particularly preferred. Herein, the term “basic”includes both the basic functional groups, such as amino groups, as wellas their salts or protonated forms, such as ammonium groups.Interchangeably the term “cationic” polyorganosiloxanes or silanes isused. The term “acidic” includes both an acidic functional group, suchas carboxyl groups, as well as their salts, such as carboxylates.Interchangeably the term “anionic” polyorganosiloxanes or silanes isused.

Especially preferred are: combinations of so-called cationicpolyorganosiloxanes or silanes, which comprise for example, amino groups(such as mentioned above), ammonium groups (such as mentioned above),quaternary ammonium groups (such as mentioned above), quaternaryphosphonium groups (such as mentioned above), with so-called anionicpolyorganosiloxanes or silanes, which comprise for example carboxylicacid groups/carboxylate groups, sulfonic acid/sulfonate groups, sulfuricacid half ester groups/sulfate groups, phosphoric ester/phosphategroups, phosphonic ester groups/phosphonate groups, phosphorig estergroups/phosphite groups, xanthate/xanthogenate ester groups.

The molar ratio of the cationic to the anionic groups in thepolyorganosiloxane or silanes is preferably selected as follows:

cationic:anionic=90:10 to 10:90, preferably 70:30 to 30:70, particularly60:40 to 40:60.

Accordingly the present invention further relates to a compositioncomprising:

-   a) at least one polysiloxane and/or silane as defined in any of    claims 1 to 10 having a functional group F selected from the group    of the acidic functional groups:    -   a zwitterionic group,    -   carboxylic acid/carboxylate group,    -   sulfonic acid/sulfonate group,    -   sulfuric acid half-ester/sulphate group,    -   phosphoric ester/phosphate group    -   phosphonic ester/phosphonate group,    -   phosphorous ester/phosphite group,        (each as previously defined)        and-   b) at least one polysiloxane and/or silane having a basic functional    group selected from amino groups, ammonium groups, phosphonium    groups and phosphine groups (each as defined above and below).

The molar ratio of cationic groups (corresponding to component b)) tothe anionic groups (corresponding to component a)) in thepolyorganosiloxanes or silanes is preferably selected as follows:

cationic:anionic=90:10 to 10:90, preferably 70:30 to 30:70, particularly60:40 to 40:60.

The content of the cationic component b) is for example 1-90 wt-%,preferably 5-80 wt-% based on the total amount of component a) and b).

It is also within the scope of the present invention, to substitute thecationic and/or anionic polyorganosiloxanes or silanes partially bycationic and/or anionic hydrocarbon compounds, wherein the termscationic and anionic must be understood as described above. Examples arecationic or anionic surfactants, such as long-chain alkyl or arylsulphonates, long-chain alkyl ammonium compounds.

According to the present invention it is also possible to combine thezwitterionic, particularly betainic polyorganosiloxanes or silanes withthe cationic or anionic polyorganosiloxanes or silanes.

In a preferred embodiment, the polyorganosiloxanes or silanes accordingto the invention have a molecular weight of <2000 g/mol, preferably of<1500 g/mol, more preferably of <1000 g/mol.

For the said polyorganosiloxanes of formulas (Ill), (IV) and (VI), n1+n2is preferably 0 to 18, more preferably 0 to 13, even more preferably 0to 10, even more preferably 0 to 5, wherein at least one siloxy groupwith R^(F) must be present.

The synthesis of thiosulfate groups containing polysiloxane or silanecompounds is also known (Silicones, Chemistry and Technology, VulkanVerlag Essen 1989, p 121).

Phosphine groups containing polysiloxane or silane compounds are forexample obtainable by alkylation of dialkyl or diaryl phosphines withthe haloalkyl-substituted siloxanes or silanes. (Organikum VEB DeutscherVerlag der Wissenschaften 1988, 17. edition, p. 203).

Phosphonium groups containing polysiloxane or silane compounds are forexample obtainable by alkylation of trialkyl or triaryl phosphines withhaloalkyl-substituted siloxanes or silanes or by alkylation of theaforementioned phosphine groups containing polysiloxane or silanecompounds (Organikum VEB Deutscher Verlag der Wissenschaften, 1988, 17.edition, p. 203).

Epoxy-polyorganosiloxanes or -silanes are advantageously prepared byhydrosilylation of unsaturated epoxy-functional compounds, such as allylglycidyl ether and vinyl cyclohexene oxide, with SiH functionalprecursors under Pt catalysis (Silicones, Chemistry and Technology,Vulkan Verlag Essen 1989, p. 90).

Carbonate-functional polyorganosiloxanes or -silanes are obtainableeither by hydrosilylation of unsaturated carbonate-functional compounds,such as allyl carbonate, with SiH-functional precursors under Ptcatalysis (U.S. Pat. No. 5,672,338, U.S. Pat. No. 5,686,547).Alternatively, they may be prepared from the corresponding epoxides byinsertion of CO₂ (DE 19505892) or by reacting aminoorganosiloxanes orsilanes with bifunctional carbonate coupling agents (WO 2005/058863).

Polyorganosiloxanes or silanes modified with isocyanate groups,including blocked isocyanate groups, are obtainable by reactingpolyorganosiloxanes which are functionalized with CH-acidic groups, suchas hydroxyl or amino functional polyorganosiloxane or silanes, with anexcess of di- or higher functional isocyanates, or by reaction ofamino-functional polyorganosiloxanes or silanes with COCl₂, or bypyrolysis of carbamato-functional polyorganosiloxanes or silanes.

Urea groups containing polyorganosiloxanes or silanes are obtainable,for example, by reaction of the above mentioned isocyanate-functionalpolyorganosiloxanes or silanes with amines.

Urethane and urea-units containing polyorganosiloxanes or silanes are onthe one hand obtainable by reaction of hydroxyl- or amino-functionalprecursors with isocyanates (Organikum VEB Deutscher Verlag derWissenschaften 1988, 17. edition, p. 429). Alternatively, urethanes canalso be obtained by reaction of aminoorganosiloxanes or silanes with forexample cyclocarbonates or carbonate-functional siloxanes or silaneswith amines (U.S. Pat. No. 5,672,338).

Amide-functional siloxanes or silanes are, for example, obtainable byreaction of aminoorganosiloxanes or silanes with lactones (DE 4318536,Example 22).

Schiff base, imine, and enamine groups containing siloxanes or silanesare, for example, obtainable by reaction of aminosiloxanes or silaneswith aldehydes or ketones, as demonstrated, for example, inWO2008113820, Example 1, and DE 4318536, Example 20a.

Hemiacetal and acetal groups containing siloxanes and silanes are, forexample, obtainable by reaction of hydroxyl-functional (COH functional)siloxanes with aldehydes to form structures, which contain hemiacetal oracetal functions (Organikum German VEB Deutscher Verlag derWissenschaften 1988, 17. edition, p. 398-400) or, as described above, byreaction of aldehyde groups containing polyorganosiloxanes or silaneswith mono- or polyvalent (particularly divalent) alcohols.

Aldehyde groups containing siloxanes or silanes are, for example,obtainable by reaction of aminosiloxanes with dialdehydes, for exampleC2 to C5 dialdehydes, with the formation of structures which, forexample, contain the combination of Schiff bases with aldehyde functionsor enamines and aldehyde functions. Alternatively, hydroxy-functional(COH functional) siloxanes can react with dialdehydes to formstructures, which contain hemiacetal and aldehyde or acetal and aldehydefunctions. (Organikum German VEB Deutscher Verlag der Wissenschaften1988, 17. edition, p. 390-400). Further, hydroxyl-functional (COHfunctional) siloxanes can react with epoxy aldehydes to these endproducts. It is also possible, to convert hydroxy-functional (COHfunctional) siloxanes by catalytic dehydrogenation on Cu and Agcatalysts into aldehydes. A further preferred group ofaldehyde-functional siloxanes are compounds which can be obtained byreaction of epoxy-functional siloxanes, for example on the basis of theaddition of allyl glycidyl ether or vinyl cyclohexene oxide and SiHprecursors, with aldehyde carboxylic acids, for example glyoxylic acidHC(═O)C(═O)OH. The preparation can, for example be carried out inaccordance with U.S. Pat. No. 5,093,518, Example 3.

Siloxane or silane-based carbobetaines are, for example, obtainable byreaction of tertiary amino structures with Na-chloroacetate (Silicones,Chemistry and Technology, Vulkan Verlag Essen 1989, p 121). On the otherhand, they can be obtained by reaction of epoxy siloxanes or silaneswith the alkaline salts of amino acids (DE 10036532, Example 1).

Siloxane or silane-based sulfobetaines are, for example, obtainable byreaction of tertiary amino structures with sultones (DE 4140447, Example1). Alternatively, they may be obtained by reaction of epoxy siloxanesor silanes with the alkaline salts of amino sulfonic acids, such astaurine, in analogy to the corresponding carbobetaines.

Siloxane or silane-based carboxylic acids are, for example, obtainableby reaction of hydroxyl- or amino-functional precursors with acarboxylic acid anhydrides, such as phthalic anhydride, succinicanhydride and maleic anhydride (DE 4318539, Example 1).

Acetoxy-functional siloxanes or silanes, for example with acyloxy groupsSi-bonded via O, are, for example, obtainable by reaction of silanoleswith acetoxy silanes (Silicones, Chemistry and Technology, Vulkan VerlagEssen 1989, p 58). Alternatively, for example, silanols andalkoxysilanes can react with acid anhydrides to form these end products.For the synthesis of such compounds it is also possible to cleavesiloxane bonds in the presence of acid anhydrides and catalysts (V.Bazant, Organosilicon Compounds, Volume 1, Academic Press New York,1965, pp. 61-64).

Siloxane or silane-based sulfonic acid derivatives are, for example,obtainable by reaction of epoxy-functional precursors with sodiumbisulfite (Silicones, Chemistry and Technology, Vulkan Verlag Essen1989, p 121).

Siloxane or silane-based sulfate derivatives are, for example,obtainable by reaction of hydroxyl-functional precursors with amidosulfuric acid (DE 431,539, Example 3).

The synthesis of silicone-based phosphate derivatives or derivatives ofphosphoric acid is, for example, described in U.S. Pat. No. 5,859,161and U.S. Pat. No. 6,175,028.

Alkoxy-functional siloxanes are, for example, obtainable by alkalineequilibration of alkoxysilanes with cyclosiloxanes (Silicones, Chemistryand Technology, Vulkan Verlag Essen 1989, p 5).

Phosphonic esters/phosphonate group-containing polyorganosiloxanes orsilanes are, for example, obtainable by reaction ofalkenyl-polyorganosiloxanes or silanes with phosphorous esters.

Phosphorous ester/phosphite groups containing polyorganosiloxanes andsilanes are, for example, obtainable by reaction ofhydroxyalkyl-polyorganosiloxanes or silanes with phosphorous esters orphosphites.

Xanthate/xanthogenate ester groups containing polyorganosiloxanes orsilanes are, for example, obtainable by reaction of alcolates of thealkoxy polyorganosiloxanes or silanes with carbon disulfide andoptionally subsequent reaction with alkyl halides to form xanthogenateester.

Via N to Si bonded organoamino groups containing polyorganosiloxanes orsilanes are, for example, obtainable by reaction ofhalogen-polyorganosiloxanes or silanes with amines.

The invention further relates to compositions comprising at least onepolyorganosiloxane and/or silane, as defined above, and at least onesolvent and/or at least one biocidal agent for the treatment oflignocellulosic materials.

The compositions of the present invention comprising at least onefunctionalized polyorganosiloxane and/or silane, as defined above, mayfor example comprise a solubilizer and/or an emulsifier whichparticularly leads to an increase in stability of the compositions ofthis invention, such as for example an aqueous composition, such as anemulsion or a solution or a dispersion in a solvent.

Suitable solubilizer or emulsifier are particularly amino-modifiedsilicones, quaternary fatty aminalkoholate, especially a quaternaryfatty aminethanolat.

Suitable solvents, depending on the method of application, are:

carbon dioxide, alcohol, water, ethane, ethylene, propane, butane,sulfur hexafluoride, nitrogen oxides, ionic liquids,chlorotrifluoromethane, monofluoromethane, methanol, ethanol, DMSO,isopropanol, acetone, THF, acetic acid, ethylene glycol, polyethyleneglycol, acetic anhydride, N,N-dimethyl aniline, methane, pentane,hexane, cyclohexane, toluene, heptane, benzene, ammonia, propanol etc.and mixtures thereof, more preferably water, organic solvents, such aspolyalcohols, such as in particular propylene glycol, ethylene glycol orbutyl diglycol, ethanol, propanol, isopropanol, n-butanol, furfurylalcohol, THF, DMSO, dioxane, aliphatic and/or chlorinated hydrocarbons,etc., or mixtures thereof.A preferred emulsion of the functionalized polyorganosiloxane and/orsilanes as defined in the present invention contains:a) at least one functionalized polyorganosiloxane and/or silane asdefined according to the invention (optionally in combination with oneor more non-inventive polyorganosiloxanes and/or silanes) in aconcentration of 1-80 wt-%, preferably 5-60 wt-%, most preferred from10-50 wt-% (wherein this amount includes the total amount of thefunctionalized polyorganosiloxanes and/or silanes as defined accordingto the present invention and of the non-inventive polyorganosiloxanesand/or silanes),b) water in an amount of 99 to 20 wt-%, preferably 95 to 40 wt-%, mostpreferred 90 to 50 wt-%,in each case based on the total amount of components a) and b),and optionally:c) one or more emulsifiers in an amount of 0-20 wt-%, preferably 0.5-20wt-%, more preferably 1-15 wt-%, most preferred from 2-10-%, preferablyselected from ionic or non-ionic emulsifiersd) one or more compounds for controlling the pH of the emulsion, such asa base or an acid, preferably an acid such as acetic acid,e) one or more solvents in a range of 0-50-%, preferably 1-50 wt-%,preferably 1-20 wt-%,wherein the amounts of the optionally present components c) to e) referto the total amount of the emulsion.

The weight ratio of the components [a)+b)] to [c)+d)+e)] is from 100:0to 100:70, preferably from 100:1 to 100:30.

The pH of such an emulsion is preferably in the range of 2-12,preferably 2-7, most preferred 3-5, which generally increases thestability of the emulsion. Optionally, the amount of component d) isaccordingly selected.

Examples of biocides, which may optionally be present in thecompositions of the present invention comprise for example:

-   -   Boron compounds, such as borax, borate, boric acid, boric acid        ester,    -   Copper compounds, such as water-soluble copper compounds such as        copper (II) salts (copper (II) oxide, micronized copper,        copper (II) sulfate, copper (II) hydroxide carbonate, bis        (N-cyclohexyldiazeniumdioxy) copper (II),    -   mixtures of boron compounds and copper compounds    -   organic biocidal compounds, such as triazoles (as azaconazole,        cyproconazole, propiconazole, tebuconazole, TCMTB)        Phenylsulfamide (such as dichlorofluanid, tolylfluanid),        carbamates (such as IPBC, carbendazim), aromatic fungicides        (such as ortho-phenylphenol, chlorothalonil) and other        fungicides (such as bethoxazin, isothiazolone), synthetic        pyrethroids (such as permethrin, cypermethrin, cyfluthrin,        deltamethrin, silafluofen), insecticides (such as imidacloprid,        flufenoxuron, chlorpyrifos, fenoxycarb).

The boron compounds are usually used in an amount of 0.1 to 300 parts byweight per 100 parts by weight of the total amount of polysiloxaneand/or silane.

The boron compounds stop microbial decomposition and allow for repellinginsects such as termites. Suitable boron compounds include boric acid,borax, boric esters, such as trialkyl borate, such as trimethyl borate,triethyl borate, tripropyl borate and tributyl borate, borates asNa₂B₈O₁₃×4H₂O or Timbor® available from U.S. Borax Inc., borax andborates such as Timbor® are preferred. An amount of boron of more than300 parts by weight deteriorates the stability of the emulsions. Whenboron compounds are used, they are preferably used in a concentration ofat least 10 wt % based on the total amount of the polyorganosiloxanesand silanes.

Further auxiliaries which can be used in the compositions of theinvention include for example: emulsifiers, as mentioned above,thickener, pigments, dyes, antistatic agents, defoaming agents, flameretardants, etc.

Preferred compositions of the invention contain ≥5 weight-%, preferably≥10 wt-%, more preferably ≥15 wt-%, most preferred ≥30 wt-%functionalized polysiloxane and/or functionalized silane, as definedabove.

Preferred compositions of the invention contain:

-   -   5 to 50, preferably 15 to 50 parts by weight of functionalized        polyorganosiloxane and/or functionalized silane, as defined        above,    -   30 to 95, preferably 40 to 80 parts by weight solvent, such as        the above-mentioned, as defined above,    -   0 to 100, preferably 0 to 80 parts by weight of further        biocides, such as the above-mentioned    -   0 to 100, preferably 1 to 80 parts by weight of other        auxiliaries, such as the above-mentioned, such as in particular        emulsifiers.

The present application further relates to a process for treatinglignocellulosic material, comprising the treatment of thelignocellulosic material with at least one polysiloxane or silane, asdefined above, or a composition as defined above, by surface treatment,immersion treatment, or vacuum or pressure impregnation.

In the method according to the present inventive the lignocellulosicmaterials may be coated or impregnated with the compositions of theinvention by all methods for introducing aqueous solutions, common inwood treatment and known from the literature, such as coating orimpregnation, for example by brushing, spraying, dipping, flow coating,hutch soaking, vessel pressure impregnation, vacuum impregnation, vacuumpressure impregnation, borehole impregnation or by the sap displacementmethod, see also “Encyclopedia of Wood AZ” (Volumes I and II), UlfLohmann, DRW Verlag, Leinfeld-Echterdingen, 2003, see, inter alia“Einbringungsverfahren” Volume I, pages 289 to 292.

Preferably a vessel pressure impregnation or a surface treatment methodis carried out, such as brushing, spraying, dipping or flow coating. Itis particularly preferred to carry out a vacuum-pressure impregnation inthe method of the present invention. The substrate to be impregnated canbe placed in a pressure-resistant impregnation reactor and subjected toa first absolute pressure of 10 to 500 mbar, preferably 50 to 200 mbarabs., particularly about 100 mbar abs. for 5 minutes to 8 hours,preferably 15 minutes to 2 hours, particularly about one half to onehour, maintaining this pressure, and then immersing the substrate in theimpregnating agent or covering the substrate with the impregnating agentand increasing the pressure to 1.5 to 20 bar abs. for 0.5 to 4 hours,preferably to 5 to 15 bar abs. for 1 to 3 hours, particularly preferredto 10 to 12 bar abs. for about 2 to 3 hours. Subsequently, the pressurecan be lowered to atmospheric pressure. The substrate is taken from theimpregnating solution, optionally affects subsequent vacuum or drainsand then conveys the vacuum pressure impregnated substrate to drying.Advantageously, a specific drying process is carried out after theimpregnation step. A specific air drying and/or a specific technicaldrying method should follow the impregnation step, for example amicrowave drying, infrared drying, fresh/exhaust air drying, hot airdrying, vacuum drying, freeze drying, or a combination of these methods,such as described, for example, in “Holzlexikon von A-Z” (Volume I andII), Ulf Lohmann, DRW Verlag, Leinfelden-Echterdingen, 2003, see,“Holztrocknung”, Volume I, page 605).

The combination of the polyorganosiloxanes or silanes used in thepresent invention with copper and/or boron and/or biocidal organicpreservatives can be used both in a preferred one-step process or in aless preferred two-step process. One-step processes are for examplebrushing, dipping or impregnating with formulations ofpolyorganosiloxanes or silanes used in the present invention in organicsolvents or as aqueous emulsions. In two-step processes, preferably thecopper and/or boron compounds and/or organic biocidal preservatives areapplied first, for example by brushing, dipping or impregnating, andthen the polyorganosiloxanes or silanes used in the present invention.

In a preferred embodiment, the polyorganosiloxanes or silanes used inthe present invention are present as an aqueous emulsion. For thepreparation and/or stabilization of such an aqueous emulsion, anemulsifier may be added, wherein the emulsifier may also be anamino-modified silicone.

It is believed that the mechanism by which the polyorganosiloxanes orsilanes used in the present invention achieve an increased resistance ofwood and other lignocellulosic materials against weather and/or humiditydeviations is at least partially effected from hydrophobing the surface,preferably the layers adjoining the surface up to the entire volume, ofthe wood or lignocellulosic material. Regarding wood, it is assumed thatthe polyorganosiloxanes or silanes used in the present invention lead toa reduced absorption of liquid water and a reduced moisture sorption(gaseous water), which in turn leads to less variation in the dimensionsin the rain or with changing environmental humidity. Thus,polyorganosiloxanes or silanes used in the present invention thereforeachieve a better dimensional stability of wood, because they penetrateinto the cell wall of the wood and remain there permanently, apparentlyby reason of their functionalization. Therefore, the wooden cell wall isalso in the dry state in a form of a pre-swollen state and thereforeabsorbs less water than untreated wood. The penetration of thepolyorganosiloxanes or silanes used in the present invention isparticularly achieved with so-called microemulsions, for example with anaverage particle size of 10 to 100 nm. Such microemulsions may penetrateinto the pores of wood cell walls and even between the cellulosestrands, thus permanently reducing the further uptake of water. In thisway, the dimensional change, such as shrinkage during the drying of thewood, is reduced when the moisture content of the environment decreases.In case of macroemulsions, for example having a particle size of greaterthan 50 to 100 nm, it is assumed that the polyorganosiloxanes or silanesused in the present invention at least partially coat the inner surfacesof the wood cells and penetrate into the pores of the wood cell wall.The polyorganosiloxanes or silanes used in the present invention on theone hand allow a greater association with the lignocellulosic materialand on the other hand provide a growth-inhibiting effect onmicroorganisms. The treatment especially effects resistance againstfungi, so that lignocellulosic materials such as wood, treated with thepolyorganosiloxanes or silanes used in the present invention, are lessaffected by staining, for example blueing fungi, or molds, ordestructive fungi (white rot, brown rot), and therefore have a greaterresistance against microbial degradation. It is believed thatimpregnation with the polyorganosiloxanes or silanes used in the presentinvention presses the moisture content in the wood below the levelrequired for growth of the fungi. By means of the polyorganosiloxanes orsilanes of the invention it is surprisingly possible to permanentlyimpregnate wood in a practical one-step process, and thus to furtherreduce the tendency of the wood to absorb water, to improve thedimensional stability in changing moisture contents of the environmentand to reduce the degradation of wood by fungi, bacteria and insects,such as wood-destroying insects, such as termites, house longhornbeetle, common furniture beetle, powder post beetles effectively. At thesame time yellowing and graying of the wood by light and weather impactis suppressed.

In a further particularly preferred embodiment of the present invention,the functionalized polyorganosiloxanes or silanes are incorporated intothe lignocellulosic material in a method using supercritical carbondioxide, or other preferably gaseous solvents (such as theabove-mentioned) as a carrier medium.

In case of the particularly preferred use of carbon dioxide this methodcomprises a pressure impact of, for example, about 10 to 400 bar atabout 0 to 180° C., especially from 50 to 300 bar at 32 to 100° C., veryspecifically 70 to 300 bar at 32 to 70° C. This process often requiresspecial decompression methods for not damaging the lignocellulosicmaterial during decompression. During decompression the generallygaseous carrier medium, such as particularly carbon dioxide, excapes andthe polysiloxanes or silanes used in the present invention remain in thelignocellulosic material, wherein generally cell walls and intercellularspaces are filled with the polysiloxanes or silanes used in the presentinvention. For more details on supercritical fluid treatments of woodmaterials reference can be made to DE 4202320, WO 2005/049170, EP1128939, EP 1146969, EP 1501664 and Morrell & Levien: “Entwicklung NeuerBehandlungsverfahren zum Holzschutz” Conference report from “Konferenzfür Holzschutz in den 90er Jahren und darüber hinaus”, Savannah, Ga.,USA, Sep. 26-28, 1994.

in a further particularly preferred embodiment of the present inventionalkoxy and/or acyloxy, preferably acetoxy-functionalized polysiloxanesand/or silanes are introduced into the lignocellulosic material by meansof a method using carboxylic acid anhydrides, especially aceticanhydride, as a solvent and reactant. Preferably, for this purpose thewood is placed in a vacuum and pressure-resistant reactor and first setunder vacuum, then a mixture comprising acetic anhydride and alkoxyand/or acetoxy-functionalized polysiloxanes and/or silanes are sucked.Preferably, at elevated pressure and temperature the wood impregnationis effected over several hours. Thereafter, excess impregnating liquidis discharged. By applying a vacuum and optionally vapor depositionvolatile compounds are removed from the wood. It is preferred to usealkoxy and/or acetoxy-functionalized polysiloxanes and/or silanes in anamount of 0.01 to 20 wt-%, preferably 0.1 to 10%, more preferably 0.1 to5 wt-% based on the weight of the wood. More technical details aboutimpregnation in the presence of acetic anhydride can be found in EP 680810. In this procedure, the weight ratio of alkoxy and/oracetoxy-functionalized polysiloxanes and/or silanes to carboxylic acidanhydrides, especially acetic anhydride, is preferably from 0.1:100 to20:100, preferably 1:100 to 10:100.

The alkoxy and/or acetoxy-functionalized polysiloxanes and/or silanes,especially acetoxypolysiloxane may also be prepared in-situ by usingpolyorganosiloxanols, in particular SiOH-terminated polyorganosiloxane,in particular hydroxy-terminated polydimethylsiloxane in the presence ofdi, tri or tetraalkoxysilanes, so that they can react with thepolyorganosiloxanols to form among others alkoxy and/oracetoxypolysiloxanes. Generally, polysiloxanes with acyloxy groupsSi-bonded via O, such as the acetoxy group, may be prepared in-situ fromthe corresponding polyorganosiloxanols, in particular SiOH terminatedpolyorganosiloxanes, in particular hydroxy-terminatedpolydimethylsiloxanes and the corresponding anhydrides.

According to the invention, it is preferred to achieve contents of thepolyorganosiloxanes or silanes used in the present invention by themethod of application or introduction of said polyorganosiloxanes orsilanes of up to 20 wt-%, preferably up to 10 wt.-%, more preferably upto 7 wt-%, especially 1 to 7 wt-%, especially about 2 to 5 wt-%, basedon the total mass of the dried treated lignocellulosic material.

Using the polyorganosiloxanes or silanes used in the present inventionit is possible to achieve a maximum protection of the lignocellulosicmaterial with a very low content of the same.

According to the invention, the content of the polyorganosiloxanes orsilanes used in the present invention in the lignocellulosic materialscan be increased by using a very concentrated aqueous emulsion of thepolyorganosiloxanes or silanes. Therefore, preferred concentrations ofsaid aqueous emulsions are at least about 5, preferably at least about10, more preferably at least about 15 wt-%, based on the total amount ofthe emulsion. Alternatively, polyorganosiloxanes or silanes can be used,wherein the preferred concentrations correspond to those of theemulsion.

The use of the microemulsions (average droplet diameter of thepolyorganosiloxanes or silanes less than 200 nm) is particularlypreferred, since the uptake into the lignocellulosic material occursvery easily. According to the invention it has been found that thepenetration depth and therefore the effectiveness of the functionalizedpolyorganosiloxanes or silanes of the present invention also dependsfrom the molecular weight and the wettability of the lignocellulosicmaterial with said functionalized polyorganosiloxanes or silanes. It isshown that especially the short-chained or low molecular weightpolyorganosiloxanes or silanes of the present invention, which are usedaccording to the invention are preferred herein. The polyorganosiloxanesused in the present invention, for example, have number averagemolecular weights M_(n) of less than 3000 g/mol, preferably less than2000 g/mol, more preferably less than 1000 g/mol (in each casedetermined by gel permeation chromatography on polystyrene as thestandard). The silanes of the present invention are low molecular weightcompounds per se and in general have a molecular weight of less than 500g/mol, more preferably less than 400 g/mol, more preferably less than300 g/mol.

EXAMPLES Example 1

Test items of size 25*25*10 mm³ (radial*tangential*longitudinal) of thewood types pine splint (Pinus sylvestris L.) and beech (Fagus sylvaticaL.) were kiln dried at 103° C. to constant mass. Subsequently, a vacuumimpregnation was carried out with an aqueous emulsion containing 10 wt-%of a sarcosin-functionalized silicon having a chain length D10 (10 Dunits), prepared according to Example 1 of DE 10036532, having thestructure

Kiln drying was carried out for 4 days at temperatures rising up to 103°C. Subsequently, a washout has been carried out according to EN 84 toremove extractable siloxanes and other materials.

This was a 14-days storage in water with multiple water exchanges. Apercentage weight increase of about 9% in average, relating to theinitial weight of each dried on-treated wood resulted.

To determine the water absorption the samples were loaded with bars andpoured with about 300 ml of water. From the weight gain after 2, 4, 6and 24 hours, the water absorption in % was calculated. In each case,the water content was related to the initial weight of the (still)untreated test items, in order to exclude an influence of the weightgain due to the treatment.

${{Water}\mspace{14mu}{absorption}} = {\frac{w_{nass} - w_{trbeh}}{w_{trunbeh}}*{100\lbrack\%\rbrack}}$w_(nass): weight of wet test itemsw_(trbeh): weight of dry test items after treatmentw_(trunbeh): weight of dry test items before treatment

It was found that the wood samples treated with the zwitterionicfunctional siloxanes showed a reduced water absorption of about 36 wt-%after 24 hours compared to the respective untreated reference.

Example 2

Test items of size 25*25*10 mm³ (radial*tangential*longitudinal) of thewood types pine splint (Pinus sylvestris L.) and beech (Fagus sylvaticaL.) were kiln dried at 103° C. to constant mass. Subsequently, a vacuumimpregnation was carried out with an aqueous emulsion containing 30 wt-%of propyltriacetoxysilane in acetic acid, additionally containing 0.07wt-% H₂SO₄.

The test items were subjected to a vacuum of 7 mbar for about 15 min ina vacuum vessel. Then the impregnation solution was sprayed and normalpressure restored (impregnation according to EN 113).

The test items were heated in the solution for 5 hours at 120° C. underreflux and in the absence of moisture (CaCl₂ tube). The test items werethen extracted with acetic acid in a Soxhlet extractor to soluble silaneor siloxane and extracted with ethanol, to remove the acetic acid. Thetest items were then dried at 103° C. to constant mass. Then immersionin water was carried out as described in Example 1. The test itemsshowed a strongly retarded absorption of water, compared to theuntreated wood samples (control). After 24 hours, this was approximately25% lower compared to the control. In addition, a permanent swelling ofthe cell wall was observed. The cross-sectional area was increased by 7%(bulking).

The Bulking could not be undone by leaching with water. The averageweight increase in the kiln dry state was about 14 wt-% based on theinitial weights of the 10 samples. The swelling-shrinkage efficiency(ASE=anti shrink efficiency) was calculated using the following formula:ASE=α_(u)−α_(t)/α_(u)*100[%]α_(u)=swelling coefficient of the controlsα_(t)=swelling coefficient of the untreated samples

${ASE} = {\frac{{\overset{\_}{\alpha}}_{u} - \alpha_{t}}{{\overset{\_}{\alpha}}_{u}} \times {100\lbrack\%\rbrack}}$

-   -   α _(u)=swelling coefficient of the controls    -   α _(t)=swelling coefficient of the treated samples.

Wherein the swelling coefficients were calculated using the followingformula:

swelling  coefficient  α = A_(dry) − A_(wet)/A_(dry) * 100[%]$\frac{A_{trocken} - A_{nass}}{A_{trocken}} \times {100\lbrack\%\rbrack}$${{swelling}\mspace{14mu}{coefficient}\mspace{14mu}\alpha} = {\frac{A_{dry} - A_{wet}}{A_{dry}} \times {100\lbrack\%\rbrack}}$

-   -   A_(dry)=cross-sectional area dry    -   A_(wet)=cross-sectional area wet

The achieved swelling-shrinkage efficiency (ASE) was in average about50% compared to the untreated reference.

Example 3

Test items of size 25*25*10 mm³ (radial*tangential*longitudinal) of thewood types pine splint (Pinus sylvestris L.) and beech (Fagus sylvaticaL.) were kiln dried at 103° C. to constant mass. Subsequently, a vacuumimpregnation (as described in Example 2) was carried out with an 100% ofpropyltriacetoxysilane. The test items impregnated in such manner wereheated in propyltriacetoxysilane at 90° C. for 5 hours, the removed fromthe propyltriacetoxysilane solution and stored at ambient condition 25°C. and 50% relative humidity for 24 hours. Then a kiln drying at 103° C.to constant mass followed and subsequently complete immersion in waterat 25° C. This was carried out as described in Example 1. The weightincrease after anew kiln drying was in average approximately 68%compared to the initial weight of the 10 test items. Compared to theuntreated wood samples a strongly retarded absorption of water wasshown; after 24 hours, this was reduced by about 70 wt-% in average.

Example 4: Reference Example without Siloxane (“Acetylated Wood”)

8 samples of pine splint (20*20*10 mm³; radial*tangential*longitudinal)were kiln dried at 103° C. and subsequently impregnated with aceticanhydride according to EN 113. The samples were then heated to 120° C.when lying in the chemical product and this temperature was maintainedfor 5 hours. After the reaction time, the samples were placed indeionized water to stop the reaction and to remove the excess aceticanhydride. The samples were left in the water for 2 days, after a daythe water was exchanged. Subsequently, the samples were dried, first atroom temperature then at 103° C.

The water absorption was tested in the kiln dried samples, by loadingthe samples in a vessel and pouring with about 300 ml of water. After 2,4, 6 and 24 hours, the weight was determined after a brief dabbing ofthe samples, which were then rapidly put back into the vessel. Therelative water absorption was calculated based on the dry weight of thesamples prior to acetylation. Then, a reduction of water absorptionafter 24 hours was calculated by relating the reduction of the waterabsorption after 24 hours, compared to the control, to the value of thecontrol. In the first water absorption his reduction was −12.8% andincreased to −34.9% in the 4^(th) water absorption.

Example 5: Synthesis of an Acetoxy-Functionalized Polydimethylsiloxane

234 g (1 mol) ethyltriacetoxysilane were introduced into a round bottomflask and 231 g (0.5 mol) of a SiOH-stopped polydimethylsiloxane of theaverage structure

with a chain length distribution of 2 to 10 and remainingcyclodimethylsiloxanes were added dropwise. During the dropwiseaddition, the temperature rose from 20° C. to about 38° C. After 5 hoursreaction the product was investigated by ¹H NMR and it was found that nofree ethyltriacetoxysilane exists any longer.

The product has the following average structure:

Example 6: Impregnation with Acetic Anhydride Acetoxy-FunctionalPolysiloxane-Mixture According to Example 5

Each of 16 pine splint samples (20*20*10 mm³;radial*tangential*longitudinal) were kiln dried at 103° C. and thenimpregnated with acetic anhydride mixed with various amounts ofacetoxy-functional polysiloxane (0%, 1%, 3%, 6%, 10%, 20 wt-%) accordingto EN 113. The samples were then heated to 120° C. when lying in thechemical product and this temperature was maintained for 5 hours. Afterthe reaction time, the samples were placed in deionized water to stopthe reaction and to remove the excess chemical product. The samples wereleft in the water for 2 days, after a day the water was exchanged.Subsequently, the samples were dried, first at room temperature then at103° C.

As can be seen from the graph in FIG. 1, the Weight Percent Gain (WPG),i.e. the percentage weight gain, sharply increases by treatment withincreasing content of acetoxy-functional siloxane. The WPG wascalculated based on the dry weight using the following formula:

${{WPG}\lbrack\%\rbrack} = {\left( {\frac{{weight}_{{after}\mspace{14mu}{treatment}}}{{weight}_{{before}\mspace{14mu}{treatment}}} - 1} \right) \cdot 100}$

But even the bulking, the permanent swelling in dry state due to thetreatment, rises. With pure acetylation (0% siloxane) it is 7.9% andsignificantly increases with 20% admixture of siloxane to 8.7%. TheBulking was calculated based on the dry dimensions using the followingformula:

${{bulking}\lbrack\%\rbrack} = {\left( {\frac{{rad}_{{after}\mspace{14mu}{treatment}} \cdot \tan_{{after}\mspace{14mu}{treatment}}}{{rad}_{{before}\mspace{14mu}{treatment}} \cdot \tan_{{before}\mspace{14mu}{treatment}}} - 1} \right) \cdot 100}$

The water absorption was determined in the samples by placing in eachcase 8 test items per treatment in a vessel, loading and pouring withabout 300 ml of water. After 2, 4, 6 and 24 hours, the weight of thesamples was determined and the relative water absorption based on thedry weight of the samples prior to acetylation calculated. Based on the24-hour values a water absorption reduction (Reduct. WA) compared to thecontrols and the acetylated samples was calculated. For this purpose thereduction of the relative water absorption in percentage points wasrelated to the relative water absorption of the controls and theacetylated samples. In the first contact with water, the waterabsorption of the combinations with polysiloxane was significantlyreduced compared to the purely acetylated samples. However, the maximumreduction of water absorption was achieved with an admixture of 6%polysiloxane. In the 4^(th) water absorption hardly any differencesbetween the different combinations with polysiloxanes were recognizable.This means that even an addition of 1% acetoxy-functional polysiloxanemay effect a maximum reduction of water absorption. Compared to the pureacetylation the combination with polysiloxane shows much betterhydrophobing.

FIG. 2 shows reduction of water absorption compared to non-acetylatedwood (black bars) and acetylated wood (shaded bars (top: 1^(st) waterabsorption, bottom: 2^(nd) water absorption).

Example 7 (Reference)

Pine splint samples 20*20*10 mm³ (radial*tangential*longitudinal) wereimpregnated with an aqueous emulsion consisting of 10 wt-% (m/m) ofamino-functional polysiloxane having an average chain length of 12siloxy units of the formula:

3 wt-% acetic acid, 5 wt-% of a mixture of three emulsifiers,(isotridecyl alcohol C13-polyethylene oxide with different polyethyleneoxide chain lengths such as Imbentin®) and 82% of water. Theamino-functional polysiloxane was prepared according to Example 22a inDE 4318536 by reaction of epoxy-functional siloxane withethylenediamine.

Subsequently, the determination of the water absorption was carried outas described in Example 6. In the first water absorption, the reductionof water absorption after 24 hours was only −8.2%, this is probably dueto the high emulsifier content, which supported a water absorption. Inthe second water absorption, the reduction was −18.6%.

In the fungi test, as described below, the samples treated with thismaterial showed a weight loss upon incubation with Coniophora puteana of9.7% (pine) and 26.9% (beech), and upon incubation with Trametesversicolor of 6.3% (beech). The values of the controls are listed in thetable below.

Example 8

Pine splint samples 20*20*10 mm³ (radial*tangential*longitudinal) wereimpregnated with an aqueous emulsion consisting of 10 wt-% (m/m) ofcarboxy-functional polysiloxane having an average chain length of 12 ofthe formula:

10 wt-% emulsifiers (as in Example 7) and 80% water.

Subsequently, the water absorption was carried out as described inExample 6. In the first water absorption, the reduction of waterabsorption after 24 hours was −11.2%, in the second water absorption anincrease of water absorption by +4.7% occurred, compared to the control.

In the fungi test, as described below, the samples treated with thismaterial showed a weight loss upon incubation with Coniophora puteana of2.7% (pine) and 14.1% (beech), and upon incubation with Trametesversicolor of 2.7% (beech). The values of the controls are listed in thetable below.

Example 9

Pine splint samples 20*20*10 mm³ (radial*tangential*longitudinal) wereimpregnated with an aqueous emulsion consisting of 10 wt-% (m/m) of amixture of the amino-functional polysiloxane as described in Example 7(80 wt.-%) with the carboxy-functional polysiloxane as described inExample 8 (20 wt.-%), 3% acetic acid, 5% emulsifier and 82% water.

Subsequently, the water absorption was carried out as described inExample 6. In the first water absorption, the reduction of waterabsorption after 24 hours was −16.5% and was increased in the secondwater absorption to −23.8%.

Accordingly, by combining the two functional polysiloxanes animprovement of the water repellency of the treated wood can be achievedcompared to the two pure products. This is particularly interestingunder the aspect, that the carboxy-functional polysiloxane has a verygood efficiency against wood-destroying fungi, whereas the absorption ofwater is increased and subject to heavy leaching. By a combination withthe amino-functional polysiloxane the leaching can be the hydrophobicitycan be improved. Mixtures of amino-functional polysiloxane tocarboxy-functional polysiloxane of 50:50 and 20:80 showed better resultsin some cases in the first water absorption, but in the second waterabsorption the combination of 80:20 was superior.

Fungi Test

A fungi test was carried out in accordance with EN 113, wherein,deviating from the standard, in each case 2 treated and 2 untreatedsamples were incubated in a Kolle flask. The table below shows theresults.

Example 7 Control (Ref.) 8 9 1 functionalisation — amino carboxy amino/carbo- (un- carboxy betaine treated) water 1. −8.2 −11.2 −16.5 −36absorption 2. −18.6 +4.7 −23.8 −21.9 [%] fungi- Coniophora 45.2 9.7 2.7⁵ 52.4 resistance puteana (weight- on pine loss [%]) Coniophora 42.626.9 14.1 ⁵ 49.3 puteana on beech Trametes 20.8 6.3 2.8 ⁵ 26.6versicolor on beech )⁵ will be provided later

The examples show that functionalized polysiloxanes or silanes of thepresent invention lower the water absorption in wood bodies. Thedecreased water absorption allows to use the functionalizedpolysiloxanes or silanes of the invention as a protective agent for woodand other lignocellulosic materials, wherein wood etc. may be made moreresistant to weather influences such as changes in the moisture contentof the environment.

It has further been shown that wood, treated with functionalizedpolysiloxanes or silanes according to the invention as a protectiveagent, is subjected to a significantly lower surface infestation by moldand blue stain fungi.

As a further advantage, the functionalized polysiloxanes or silanes ofthe present invention used as a protective agent for lignocellulosicmaterials, such as wood, offer an increased resistance to infestationwith harmful algae and marine organisms, such as piddock. As a furtheradvantage, the functionalized polysiloxanes or silanes of the inventionused as a protective agent for wood, offer an increased resistance toinfestation with algae.

Further, the functionalized polysiloxanes or silanes of the presentinvention can increase the resistance of wood against wood-destroyinginsects, such as termites, house longhorn beetles, common furniturebeetles, powder post beetles.

Furthermore, degradation experiments, i.e. measurement of mass loss ofbeech and pine in contact with the white rot fungus Trametes versicolorand the brown rot fungus Coniophora puteana, that functionalizedpolysiloxanes or silanes according to the invention increase resistanceof wood and other lignocellulosic materials against these wooddestroying fungi.

Experiments on the swelling and shrinkage behaviour of beech and sprucewood samples show that the functionalized polysiloxanes or silanes ofthe present invention provide wood with an increased dimensionalstability when exposed to water or humidity of the environment. This isa desired property, as swelling and shrinkage is a major disadvantagewhen using wood. For example, the increase in the dimensional stabilityleads to a significantly reduced cracking, as has been demonstrated inweathering tests.

Experiments in outdoor exposure revealed that wood samples treated withthe functionalized polysiloxanes or silanes according to the invention,exhibit an increased color stability. This protection can be ascribed tothe fact that in particular the lignin degradation in the upper layersof the cell walls of the wood takes place less rapidly than in untreatedwood.

The leaching experiments with boric acid as a co-biocidal agent fordetermining the fixation of hydrophilic substances by the functionalizedpolysiloxanes or silanes of the present invention in lignocellulosicmaterials show that the functionalized polysiloxanes or silanes of thepresent invention achieve a fixation or retention of hydrophilicsubstances in wood or lignocellulose materials. The fixation orretention even of lipophilic substances in lignocellulosic materials bythe functionalized polysiloxanes or silanes according to the inventionderive from the general lipophilic properties of these siliconederivatives. Therefore, the functionalized polysiloxanes or silanes ofthe present invention are also suitable for fixation of conventionalwood treatment agents, such as flame retardants, fungicides,insecticides or dyes. This particularly applies to such conventionalcompounds which are poorly retained in the matrix of the lignocellulosicmaterial and are easily washed out by water.

To detect a reduction of flammability, pine wood impregnated with thefunctionalized polysiloxanes or silanes according to the invention areexamined using a thermo-balance (TGA). Therefore, pine wood samples ofthe size 5×10×30 mm³ are treated with the functionalized polysiloxanesor silanes of the present invention as well as with a commercial flameretardant for wood (Impralit F3/66, Ruetgers Organics). The wood samplesare then ground. By means of a thermo-balance (STA 409 PC, Netzsch), thewood flour is continuously heated from 0° C. to 800° C. under oxygen asa shielding gas with a heating rate of 20° C./min, and the weightchanges are measured. The thermogravimetric analysis shows that thefunctionalized polysiloxanes or silanes of the present invention, leadto a higher flame resistance or fire resistance of the so treatedlignocellulosic materials, as demonstrated on the example of wood. Thisis particularly the case if in addition to the functionalizedpolysiloxanes or silanes of the present invention, conventional flameretardants are applied to the lignocellulosic material, such as those ofphosphor compounds (phosphates, polyphosphates), magnesium compounds(magnesium hydroxide), aluminum compounds (aluminum hydroxide),bromine/chlorine compounds (hydrogen halides) and flame retardantsystems with expanding materials.

The functionalized polysiloxanes or silanes of the present invention mayalso be used for the physical and/or chemical bonding of conventionaltreatment agents for wood and other cellulose-based materials, thusincreasing its resistance. This particularly related to the combinationof functionalized polysiloxanes or silanes according to the inventionwith flame retardants, insecticides or dyes, especially those compounds,which are particularly stable in a hydrophobic environment or retainedtherein.

Furthermore, wood treated with functionalized polysiloxanes or silanesaccording to the invention may comprise more resilient surfaces, i.e.for example harder and/or abrasion resistant surfaces.

The invention claimed is:
 1. A method for treating lignocellulosicmaterials to protect them against microorganisms, insects and fungi,comprising applying a polyorganosiloxane to said lignocellulosicmaterials by a procedure selected from the group of surface treatment,immersion treatment, or vacuum or pressure impregnation to form acoated- or impregnated-lignocellulosic material wherein saidpolyorganosiloxane is selected from polyorganosiloxanes of the formula:

wherein n is in number average 0 to 28, wherein the radicals R¹represent organic radicals, which may be the same or different, with theproviso that at least one of the radicals R¹ is a radical R^(F) whereinR^(F) is selected from the group of functional groups consisting of: (i)aldehyde groups, (ii) zwitterionic groups containing radicals selectedfrom:

or its neutral form:

wherein R² represents hydrogen, a monovalent straight-chained, cyclic orbranched, saturated, unsaturated or aromatic hydrocarbon radical havingup to 60 carbon atoms, which may contain one or more groups selectedfrom —O—, —S—, —NH—, —C(O)— and —C(S)—, and wherein R² may optionally besubstituted by one or more substituents selected from the groupconsisting of a hydroxyl group, an optionally substituted heterocyclicgroup, optionally containing one or more nitrogen atoms, amino,alkylamino, dialkylamino, ammonium, polyether radicals and polyetherester radicals, wherein in case that multiple groups —N R² are present,these may be the same or different, and R³ are the same or different andR³ is a divalent, straight-chained, branched, cyclic, aliphatic,unsaturated, or aromatic hydrocarbon radical having up to 30 carbonatoms, which may contain one or more groups selected from —O—, —NR⁴—,wherein R4 is hydrogen or C1-22-alkyl, —C(O)— and —C(S)—, and which mayoptionally be substituted by hydroxy and is bonded to the silicon atomvia carbon, and (iii) zwitterionic groups containing radicals selectedfrom:

or its neutral form:

wherein R² and R³ are the same or different and are as defined above,and optionally a functional group selected from the group consisting of:phosphonium group, phosphine group, carbonate group, urethane group,isocyanate group including blocked isocyanate group, urea group, amidogroup, hemiacetal and acetal group, enamine group, imine group, sulfonicacid/sulfonate group, sulfuric acid half-ester/sulphate group,phosphoric ester/phosphate group phosphonic ester/phosphonate group,phosphorous ester/phosphite group, xanthate/xanthogenate ester group,organo amino group Si-bonded via N, hydroxy group, acyloxy groupSi-bonded via O, alkoxy group Si-bonded via O, and thiosulfato group andsalts thereof.
 2. The method of claim 1, wherein the molar content ofthe radicals RE is from 3.33 to 100 mol-%, based on the number of siloxyunits.
 3. The method of claim 2, wherein the molar content of theradicals R^(F) is from 5 to 100 mol-%, based on the number of siloxyunits.
 4. The method of claim 3, wherein the molar content of theradicals R^(F) is from 5 to 50 mol-%, based on the number of siloxyunits.
 5. The method of claim 4, wherein the molar content of theradicals R^(F) is from 10 to 50 mol-%, based on the number of siloxyunits.
 6. The method of claim 5, wherein the molar content of theradicals R^(F), is from 10 to 30 mol-%, based on the number of siloxyunits.
 7. The method of claim 1, wherein R² is a saturated hydrocarbonradical having up to 24 carbon atoms, which may contain one or twogroups selected from —O—, —S—, —NH—, —C(O)— and —C(S)—, and which mayoptionally be substituted by one or two hydroxyl groups.
 8. The methodof claim 1, wherein R³ is a divalent saturated aliphatic hydrocarbonradical having up to 20 carbon atoms, which may contain one or two —O—groups, and which may optionally be substituted by hydroxy, and which isbonded to the silicon atom via carbon.
 9. The method of claim 7, whereinR³ is a divalent saturated aliphatic hydrocarbon radical having up to 20carbon atoms, which may contain one or two —O— groups, and which mayoptionally be substituted by hydroxy, and which is bonded to the siliconatom via carbon.